1. Field of the Invention
The present invention relates to a moving image processing apparatus, a moving image playback apparatus, a moving image processing method, a moving image playback method, and a storage medium.
2. Related Art
As represented by a digital video camera and the like, image capturing apparatuses that can simultaneously record moving images and sounds are common. Among such image capturing apparatuses, there are some that perform multiplexing of encoded and packetized audio data and moving image data into a file with synchronization information being embedded in the packet header of the audio data for the purpose of audio-video synchronization. Also proposed is a technique in which the frame rate can be arbitrarily changed while capturing a moving image and, in accordance with the changed frame rate, a sampling rate of audio data to be recorded is changed, thereby avoiding a sense of discomfort from being felt while listening to the sound (See Japanese Patent Application Publication No. 2004-180289, for example).
However, with the conventional technique described above, since the sampling rate of audio data is changed in accordance with the changed frame rate, when a moving image with sound recorded at a high frame rate, e.g., 60 fps (Frames Per Second), is played back at a normal frame rate, e.g., 30 fps, the sound is also played back at half speed and becomes hardly audible. It will become much less audible, in a case of an image capturing apparatus recently launched in the market that can capture a moving image at a higher frame rate of 120 fps.
Alternatively, there is proposed another technique that records sound only when a moving image is recorded at a normal frame rate, but does not record sound when a moving image is recorded at a high speed. With such a technique, however, a silent moving image is played back when the moving image captured at high speed is played back at the normal frame rate by frame skipping or the like, and it will be tedious to a user.